COLUMBIA-Shawn Humphries apologized to his victim's family before he was put to death by lethal injection Friday night for the 1994 murder of a Simpsonville store clerk.

Humphries mouthed 'I'm sorry' before fatal chemicals were pumped through his veins. Department of Corrections officials pronounced Humphries dead at 6:18 p.m.

Humphries was convicted of murder for the shooting death of Mendal Alton 'Dickie' Smith on New Year's Day 1994. Prosecutors said Humphries and a friend decided to rob the store where Smith was working after they had been drinking beer all day.

Humphries' attorney Teresa Norris read a 1 ½ -page handwritten statement from the death chamber before the execution in which Humphries apologized for the killing and used Bible verses to criticize the death penalty.

'I hope that my execution brings the Smith family some peace,' he wrote. 'But now I want to say something to everyone who supports this or any execution. We are all sinners, so what gives you the right as a sinner to take away a gift that God gave?'

At the end of the statement, Humphries looked toward the victim's sisters, Kathy Smith Carpenter and Carol Smith Cooley, and mouthed 'I'm sorry.'

Carpenter nodded in response. It appeared that a tear rolled down Humphries' cheek after the exchange.

After the execution, Carpenter said she appreciated the gesture.

'Shawn gave me something very special tonight when he said to me through the window that he was sorry,' Carpenter said. 'That was the greatest gift that I could have ever received.'

Officials said Humphries requested a McDonald's hamburger, french fries, broccoli and cheese, and oat cereal for his last meal.

Before the curtains opened at 6:03 p.m., the victim's widow, Patricia Smith, looked toward other family members and whispered 'I can't do it,' and walked out of the viewing area without witnessing her husband's killer being put to death.

Humphries, his eyes closed, swallowed rapidly several times as the lethal chemicals began flowing through his veins.

After his chest heaved several times, his mouth fell open, after which he did not move or appear to breathe again.

Carpenter and Cooley kept their gaze trained on Humphries from the time the curtain was opened until it was closed following the pronouncement of death.